National Nathusius' Pipistrelle Project

Bat monitoring activities are currently restricted in order to comply with government guidance on controlling the COVID-19 pandemic.

For more information see our statement on COVID-19 and NBMP surveys.

Nathusius' pipistrelle is considered rare in the UK but may simply be under-recorded. It is often found at large waterbodies, particularly during its autumn migration period.

The National Nathusius' Pipistrelle Project was launched in 2014 with a grant from the People's Trust for Endangered Species, to improve our understanding of the ecology, current status and conservation threats for Nathusius' pipistrelles in Great Britain.

The aims of the project are to:

  • Determine the resident and breeding status of Nathusius' pipistrelle in Great Britain.
  • Determine the migratory origins of Nathusius' pipistrelles in Great Britain.

Survey methods

1. Identify hotspots of Nathusius' pipistrelle activity using acoustic bat detector surveys. Many Nathusius' pipistrelle hotspots have already been identified by BCT's earlier Nathusius' Pipistrelle Survey which ran from 2009-2014.

2. Using harp traps and acoustic lures in activity hotspots, trap individuals under licence and ascertain their breeding status, collect a dropping, a fur sample and, if an experienced bat ringer is part of the project team, ring each individual.

3. If females are captured in the pre-breeding period, undertake radio tracking to locate potential maternity roosts.

4. Stable isotope analysis (in collaboration with the University of Exeter) of fur samples to determine latitudinal provenance and assess migration patterns of the bats.

Take part

This project is open to all groups. Different aspects of the project can be undertaken depending on the experience and equipment available within the group. For further information please contact Philip Briggs at

Key results so far

National Nathusius' Pipistrelle Project

Nathusius' pipistrelle captures April 2011 to October 2019. At each site there may be records falling into more than one category but the symbol indicates the level to which breeding or potential breeding has been identified: breeding females (confirmed breeding that year) > juveniles (potentially born locally, though may have come from elsewhere) > other adult females (some had bred in the past but no evidence of breeding that year) > males only caught.

  • Based on data received to date, from April 2011 to October 2019, there have been 2,689 Nathusius' pipistrelles captures (including some recaptures of individuals). Twenty-four were currently breeding females, 456 were adult females who showed no evidence of breeding that year (99 had bred previously though whether at that particular site or even in the UK is not known), 1,872 were adult males, 302 were juveniles, and 38 didn't have the sex and/or age recorded.
  • Work carried out by the University of Exeter on stable isotopes in the fur samples of Nathusius pipistrelles caught during this project suggests that these bats have a migratory origin further northeast than the UK, and that the Nathusius’ pipistrelles originated from more northerly latitudes than soprano pipistrelles.
  • Maternity colonies have been discovered in Kent, Northumberland and on the Surrey/Greater London border.
  • Ten long distant migratory records have been found: a bat ringed in North Somerset was rediscovered in Holland in December 2013; a bat ringed in Latvia was recaptured in East Sussex in October 2015; two bats ringed in Lithuania were recaptured in Kent in August and October 2016; and two bats ringed in Latvia turned up in Greater London in August and September 2017; a bat ringed in Latvia turned up in Essex in September 2017; a bat ringed in East Sussex was found in Belgium in September 2018; a bat ringed in Northumberland was found in Poland in May 2019; and a bat ringed in Greater London was found in Russia in August 2021. The minimum distances travelled are shown below.
National Nathusius' Pipistrelle Project

Why are we running this project?

Migration patterns of Nathusius’ pipistrelle are relatively well known in mainland Europe but the movements of bats in and out of the UK and their migration routes and origins are not known. This project will provide the first attempt to understand the migratory activity of Nathusius’ pipistrelles in the UK through stable hydrogen isotope analysis and will contribute to the overall understanding of migration across its distribution.

Nathusius’ pipistrelle has been identified to be at high risk of mortality from wind turbines in Europe. Because Nathusius’ pipistrelle is a migratory species, wind turbines have the potential to impact upon bat populations at a range of geographical scales. This project will provide vital information on the migratory origins of Nathusius’ pipistrelles in the UK and allow us to assess the potential threat of wind turbines to bat populations both in the UK and beyond.

The recorded range expansion of Nathusius’ pipistrelle has been shown to be linked to climate change and future climate change is predicted to have further impact on this species’ distribution. Comprehensive information on the distribution and status of the species in the UK currently is therefore essential to determine a full understanding of the effects of future climate change and to take appropriate action to ensure the conservation of this species in the UK.

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